A method of supporting a tool (106) in an assembled apparatus (10) comprises the steps of (a) inserting a support structure (60) through a first aperture (52,56) in a casing (50,54) of the apparatus (10), a first end (62) of the support structure (60) being outside the casing (50,54) and a second end (64) of the support structure (60) being inside the casing (50,54), (b) securing the first end (60) of the support structure (60) to the casing (50,54), (c) arranging a first portion (78) of the support structure (60) to abut at least one surface within the casing (50,54), (d) inserting a tool (106) through the first aperture (52,54) or a second aperture in the casing (50,54), and (e) securing the tool (106) to a second portion (102) of the support structure (60) within the casing (50,54).